This dataset contains a set of observed monthly climate variables on a 5km resolution grid. The observations are derived from 16 daily climate variables that have been averaged (e.g. daily maximum temperature) or summed (e.g. monthly total precipitation) over calendar months. The input station data originate from the Met Office Integrated Data Archive System (A version of MIDAS is also available through CEDA, although incremental developments to the database such as quality control and data recovery activities may result in some differences compared to the database at the time of production of the UKCP09 data). The gridding process accounts for effects such as latitude, longitude, altitude, coastal influence, and the effect of urban land through the use of normalisation with respect to monthly 1961 – 1990 climate normals, and in the case of some variables a regression model. For more details about the construction see Perry and Hollis (2005). The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

This dataset contains a set of reference long term averages for observed climate variables on an approximately 25km resolution grid. This matches the resolution of the HadRM3 regional climate model and the UKCP09 climate projections. These data represent the baseline reference climate averages for the period 1961 – 1990. The data were derived from the Met Office gridded land surface climate observations – long term averages at 5km resolution (see related dataset). Each 25 x 25km grid box value is an average of the 5 x 5 km grid cell values that fall within it. Averages have been calculated for each month, season and the year as a whole (17 data sets). For the days of frost and days of rain variables the seasonal and annual averages are the total of the individual monthly averages. For the remaining variables the seasonal and annual averages are the mean of the monthly averages (allowing for differences in month length). To facilitate combining the baseline data with the UKCP09 climate projections, the 25 km baseline averages for rainfall have been expressed in units of millimetres per day (rather than total millimetres, as for the 5 km data sets). The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

This dataset contains a set of daily observations of temperature (daily maximum, daily minimum and daily mean temperature) and rainfall (24 hour accumulation) interpolated to a uniform 5km grid resolution covering the period 1960 to 2014. The input station data originate from the Met Office Integrated Data Archive System - MIDAS - a database at the Met Office of observation station data stretching back to the 18th century. (A version of MIDAS is also available through CEDA, although incremental developments to the database such as quality control and data recovery activities may result in some differences compared to the database at the time of production of the UKCP09 data - see linked datasets for access to these equivalent datasets held by CEDA). The input station data used provide observations relating to periods 0900 to 0900 UTC, so the gridded output stored against day "dd" are as follows: • Maximum temperature between 0900 on day dd and 0900 on day dd+1 (normally expect to occur during the afternoon of day dd) • Minimum temperature between 0900 on day dd-1 and 0900 on day dd (normally expect to occur just before dawn on day dd) • Mean temperature that is the average of the maximum and minimum temperature • Rainfall (or rainfall equivalent in cases of frozen precipitation) amount between 0900 day dd and 0900 day dd+1 The gridding process accounts for effects such as latitude, longitude, altitude, coastal influence, and the effect of urban land through the use of normalisation with respect to monthly 1961 – 1990 climate normals, and in the case of temperature, a regression model. The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

This dataset contains a set of observed climate indices on a 5km resolution grid. The data are derived from daily temperature and precipitation grids (see related dataset) to provide annual indicies: 9 temperature based indices (for example summer heatwave duration); and 12 precipitation indices (for example maximum 1 day precipitation amount). The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.